1. Field of the Invention
The present invention relates to a level for measuring the inclination of a surface in all directions.
2. Description of the Prior Art
A variety of levels designed to measure the inclinations of surfaces in all directions have been proposed heretofore, such as a level, for instance, constructed of an indication bubble enclosed in a round, flat case. This kind of level, however, is very expensive and is not suitable for mass-production when it is formed of a large size which is easy to see.
In another level wherein a ball is held in a round, flat case whose inner bottom surface is formed as a concave circular-arc surface, it takes a long time for the ball to come to rest, and the internal concave surface must be formed to a high degree of precision in all directions, which makes this type of level expensive as well.
A third type of level is constructed by arranging two unidirectional levels at right angles in the same plane or a base plate. This level necessitates sequential checking of two measurement points, which makes the operation thereof time-consuming.